(1) Field of the Invention
The invention is concerned with binder systems for use in the manufacture of high strength composites and the composites produced thereby, especially paper, paperboard, hardboard and insulation board.
(2) Description of the Prior Art
The use of a latex in the manufacture of paper by wet-end addition, or as a beater additive, is well known. Commonly, the latex has been an anionic latex but a water-soluble cationic deposition aid has been used therewith. Because of the slightly anionic nature of pulp, it has been suggested that a low-charge density cationic latex should be used in order to get good deposition on the fibers without the use of a deposition aid. Combination of anionic and cationic wet-end additives in which both species are water soluble are known. However, the combination as wet-end additives of a cationic latex with a water soluble anionic polymer, particularly latexes having particles with a high density of pH independent bound charge at or near the particle surface has not been disclosed.